This project proposes a program of research that combines visual neuroscience and behavior analytic perspectives to investigate facial emotion understanding in individuals with mental retardation. With the new technologies available, research that has been conducted to examine these questions with young children an clinical populations can now be applied to the field of mental retardation. There is also a wealth of work on the general topic of stimulus control with individuals with mental retardation but those studies have so far, had little influence on research that seeks to understand the basic processes involved in the understanding of facial expression. We will draw from these conceptual and procedural traditions to refine existing methods and develop new ones to examine the nature of facial discriminations and facial emotion understanding in individuals with severe intellectual disabilities. A further goal of this project is to examine ways to establish facial emotion discrimination in individuals who exhibit specific difficulties with these skills. Thus, the methods are directly related to the issue of remediation. The Specific Aims are to: (1) Ascertain the ability to discriminate faces on the basis of identity and emotional expression in populations of individuals with mild to severe levels of mental retardation and typically developing children. (2) Examine methods to remediate deficits in facial identify or emotional expression discriminations. (3) Determine the visual information and scanning strategies that are used to discriminate among facial emotion expression. (4) Evaluate the classification of emotional expression across stimulus modalities (line drawings, color photographs, and full motion video). (5) Examine methods to remediate deficits in classification across modalities. (6) Assess the receptive and expressive understanding of verbal labels that refer to specific emotions. (7) Examine methods to remediate deficits in associating verbal label with specific emotions. (8) Contrast neural processing in individuals with and without mental retardation who are able to successfully discriminate facial emotion expressions, and refine the methods that will be needed to explore issues of neural processing in individuals who experiences difficulties in understanding facial emotion expressions.